Are they any guide lines on how much percentage of the system resources should be given to Default Resource partition in priority scheduler in TASM. Earlier releases we used to give more weightage than any other RP so that system work can get faster, is this still holds good?

When there is production support workload, used for the purpose of troubleshooting data issues and needs a gaurented decent response, why not have it in RP0 under Low AG locked down to 1.8% CPU (out of the total 25% allocated to RP0 with absolutely no workloads other than production support under 'L'.

Sounds like an overkill to create a separate RP for just this workload, which is as important as system or at least comes right next to it.